It was impossibly expensive, extraordinarily dangerous, and as a secret weapon, completely unarmed. For the American military, the state-of-the-art submersible, christened NR-1, would be the most closely guarded-and revolutionary-secret of the Cold War. The pet project of Admiral Hyman Rickover, the father of the nuclear Navy, the 400-ton submarine with a miniature nuclear reactor was designed to dive deeper than any other submarine. But such depths also meant the crew would be cut off from all possible rescue should something go wrong. Now, the full story of the NR-1 is told for the first time through eyewitness accounts by the original crew-including co-author Lee Vyborny-who dared go where no men had gone before.